Ignition magneto



Patented Feb. 22, 1938 IGNITION MAGNETO Umberto Quintavalle,

Milan, Italy, assigner to Fabbrica Italiana Magneti Marelli Soc. An.,

Milan, Italy Application September l, 1936, Serial No. 98,985

In Italy September 20, 1935 'l Claims.

` "Ihe present invention relates to ignition magnetos particularly for internal combustion engines and has for its object an arrangement for coupling the rotatable parts of such magnetos with their driving member. said arrangement making the construction simple and improving the conditions in which said rotary parts are driven into rotation.

In accordance with the present invention thev rotary members, as the Inductor magnet or the magnetic flux distributor or also the armature, with the respective pole shoes and generally speaking the parts intended to rotate therewith, and also the shaft actuating the high voltage current distributor, if any, are connected each directly and independently of each other with a driving member which in turn is driven by the engine or a prime mover generally. A

On the annexed drawing an embodiment of this 'invention in an ignition magneto of the class including a rotary star-shaped permanent magnet inductor is illustrated by way of example, and

Fig. lis a section of concerned parts of such a magneto with parts removed and on line I-I of Fig. 2,

Fig. 2 is a transverse section on line 2-2 of Fig. 1.

In the illustrated embodiment, I is the magneto casing and 2 denotes the windings in which current is induced said windings being located on a laminated core 3 whose ends are connected with arms l-l' having pole shoes 5 8', the whole of parts 2, 3, l, l', l, l' providing the magneto stator, as well known in the art.

8 is a permanent magnet intended to induce currents in coils 2 by enact of its revolution with respect to said. core and pole shoes, said magnet being star-shaped as illustrated to provide pole faces on which pole shoes as 1 are located; 8 is a` shaft concentric with magnet 6 and intended to drive the high voltage current distributor (not illustrated) in rotation.

In the illustrated embodiment the rotary parts of the magneto are driven in rotation by means of a tubular shaft 8 supported in the magneto casing by means of an antifriction bearing III and idly embracing an extension II of shaft 8 with insertion of an antifriction lining.

The tubular shaft 8 provides one member of an advance governor referenced in its whole by II and being of the class described in Acopending application led on July 414, 1936, Ser. No. 90,607, now Patent 2,093,376, September 21, 1937. Another member of said governor is a cup I3 having a central ori'flce in its bottom wall Il through which the shaft 8 extends.

The construction and operation of governor I2 are not described in detail in the present application being suilicient for the purposes of this invention to state that the governor operation causes the cup I8 to be driven by shaft 8 with a variable respective angular` setting such setting depending upon the speed of parts 8 and I8.

In accordance with the present invention the driven parts of the ignition magneto, that is the magnet 8 and its polar shoes 1 and the distributor shaft 8, are connected each directly and separately or severally with .the member intended to drive them such member being the shaft 8 or a member connected with it as the bottom wall il of the cup I3 connected with shaft 9 in the illustrated embodiment.

The driving engagement of magnet 6 with part I4 is provided by means of fingers I 8 projecting from the face of said part I4 and entering co operating depressions intermediate the arms'of the star shaped magnet 8.

The laminated pole shoes 1 provided on the ends of magnet arms are connected with part Il lby means of studs I6 which extend throughout the thickness of the cooperating shoe 1 in a direction parallel with the axis of shaft 8; each of said studs has one end fast on part -II by means of a riveted head I1 and a cooperating flange I1 while its opposite end provides a riveted head I8 which engages a ring or disk I9 located on the adiacent end of magnet 6 and extending over the ends of the several pole shoes 'I.

The shaft 8 is in turn connected with the disk I4 by means of a pin or cotter 2li fast transversely in a hole of shaft 8 and having extended end portions which engage notches 2| provided in the part Il as extensions of hole made in said part Il for the passage of shaft 8 therethrough.

The drive imparted to sleeve 9 for actuating the movable parts of the magneto acts 'on part Il through the operation of governor I2 and the several members of the magneto are driven in rotation severally by said part Il, the magnet 8, pole shoes 1 thereof and shaft 8 being driven by part Il by means of respective engaging means I5, I8 and 20. I

By the described arrangement the central shaft 8 may have a very reduced cross section because it is only required to actuate the high voltage current distributor.

On the other hand in view of described arrangement for the drive of the star magnet 8 this magnet does not require to be machined to an inciV tricate shape and it is emciently engaged by iingers I5 which extend into recesses inherently provided between the arms of said star-shaped magnet. Finally the pole shoes 1 of the magnet 6 do' not produce a stress on the magnet in respect of their drive through such magnet, they being driven directly by studs I6 and part I4.

As above described the stresses operative in the several driven parts are reduced to a minimum because each of them is connected directly with the driven member in best manner having regard to its nature, structure and operation; accordingly the size and weight of the several parts may be materially reduced with respect to known constructions.

Of course the present invention is not restricted to its described and illustrated embodiment and it includes all equivalent constructions; say an armature having windings thereon or a magnetic flux distributor may be used instead of magnet 6.

Further the governor I2 may be omitted, the driving part i4 being then connected directly with shaft 9, or an equivalent governor of any preferred construction may be used.

What I claim as my invention and desire to secure by U. S. Letters Patent is:-

L In an ignition magneto including a driving shaft and a rotor consisting of a number of parts, a governor, a mover driven by said shaft through said governor, and means on said mover and individual rotor parts for connecting each of said rotor parts in rotation with said mover directly and individually.

2. In van ignition magneto including a mover and a rotor comprising magnet pole shoes, studs extending through said pole shoes and having one of their ends fast in said mover, a clamping member extending over the ends of said pole shoes opposite to said mover, and means on the opposite ends of said studs for engaging said clamping member and pole shoes in position.

3. In an ignition magneto, a rotary element comprising a driving member, a disc-shaped part connected with said driving member and a plurality of driven parts each of said driven parts being directly and individually connected with said disc-shaped part.

4. In an ignition magneto, a rotary element comprising a driving member, a disc-shaped part connected with said driving member and a rotor comprising magnet pole shoes, said rotor and magnet pole shoes being directly and individually connected with said disc-shaped part.

5. In an ignition magneto, a rotary element comprising a driving member, a disc-shaped part connected with said driving member, a rotor comprising a magnet having radially projecting arms and pole shoes at the ends of said arms, dogs fast to and projecting from said disc-shaped part and entering recesses intermediate said magnet arms for interconnecting said magnet and disc-shaped part and means for connecting said pole shoes directly with said disc-shaped part.

6. In an ignition magneto, a rotary element comprising a driving member, a disc-shaped part connected with said driving member, a rotor, magnet pole shoes and a shaft for the drive of a high voltage distributor, said rotor, pole shoes and shaft being directly and individually connected with said disc-shaped part.

7. In an ignition magneto, a rotary element comprising a driving member, a disc-shaped part connected with said driving memberl and having a central bore, a rotor and magnet pole shoes, said rotor and pole shoes being individually connected with said disc-shaped part on a face of said disc-shaped part and a shaft for the drive of a high voltage distributor, said shaft entering said bore of said disc-shaped part, a pin extending transverse to and through said shaft and having its ends projecting from said shaft and engaging cooperating recesses in the portion of said disc-shaped part encircling said bore.

UMBERTO QUINTAVALLE. 

